***2015 LC Maths Paper 1 - Higher Level - June 5th***

Chef Tony

AnnaTorvFan wrote: »

Was the oil spill (can't remember what word they used for it) a cylinder or a circle?

Cylinder I believe as they gave it a height of .1 cm

Magnate

I've seen too many wrong answers, I'm definitely out! :P

Dianabluex

MmmPancakes wrote: »

Am I the only one who got 88 for the angle of the plane?

I got that

Chef Tony

Bah_Humbug wrote: »

I got 2 degrees, and 90 - 88 = 2 so there's something there maybe
How did people get 15?

From above :


You work out in the previous question the derivation of the function, then you use this derivation as the slope into the tan0=m1+m2/1-m1m2 formula (in the line section of the log tables), using the x axis as the other slope, which is 0, to get its angle from the ground at a certain point

Do You Even Squat

Kremin wrote: »

It was 14. You have to realise the ball goes down AND UP.. so you multiply by 2... but take away two at the end because it drops from 2metres and doesnt go up 2 metres again.


I honestly think i might have got 300/300 for that paper, did anyone else get 16* SOUTH OF EAST for the plane question? What I did was find the slope and let it equal to tanalpha

Im pretty confident it was 2. tan inverse (.0288?) is 1.68ish

simplyno1

MmmPancakes wrote: »

Am I the only one who got 88 for the angle of the plane?

I got 46 degrees, used the tan m1 m2 formula... other people answers are just making me worry that i got the wrong value for what f'(-4) is in the part before that (b)(i).

YouKnowNothing

gryfothegreat wrote: »

Wasn't too bad! Very strange paper though, very heavy on integration and differentiation, no proof by induction or bijectivity or logs and indices... That DeMoivre Q was BS! Also I got 91.25 hours for the length of a day haha... Onwards to Paper 2!

You were nearly there! 91.25 is the day, just have to put it into the formula for the hours

Kremin

Chef Tony wrote: »

From above :


You work out in the previous question the derivation of the function, then you use this derivation as the slope into the tan0=m1+m2/1-m1m2 formula (in the line section of the log tables), using the x axis as the other slope, which is 0, to get its angle from the ground at a certain point

i let it equal tan0 too, mainly because I knew slope = tan0 from applied maths linear motion.

Doctorhopeful

Chef Tony wrote: »

What did people get for the plane question about its angle from 4km away? I got 15 degrees after rounding and it seemed about right

I got two degrees. 15 seems way too steep considering it's dropping 150 metres in 5000 metres.

simplyno1

MmmPancakes wrote: »

Am I the only one who got 88 for the angle of the plane?

I got 46 degrees, used the tan m1 m2 formula... other peoples answers are just making me worry that i got the wrong answer when it asked you to sub in x = -4 to the first derivative

DarraghF197

Kremin wrote: »

I got both too, initially i replaced 1 with w^n because it said the complex number was equal to that, and hten i rearranged the sequence and got 0. but doing it different ways got different results so i dont know.

Yeah, I phrased my wording a bit bad there. When I got zero, I thought it couldn't right. So I changed the sum to let the n equal n rather than n-1. Then got -1/w which I was happy with.

simplyno1

Doctorhopeful wrote: »

I got two degrees. 15 seems way too steep considering it's dropping 150 metres in 5000 metres.

can you remember what answer you got for subbing -4 into the first derivative? because that gave you the slope. so it would be a factor in the answer for the degrees... most likely how there is such a big difference. I got -0.02886 for that part.

jameshan

Do You Even Squat wrote: »

Im pretty confident it was 2. tan inverse (.0288?) is 1.68ish

**** I left my Calculator in Radians and got 0.0289 when i uesed tan( inverse

AnnaCU

AnnaTorvFan wrote: »

Pretty sure I got either 88 or 89.

Did anyone else get 8m as the last part for Q1?

yeah, i got 8 too

MmmPancakes

This was my thinking (can't remember the value for m1, though) http://prntscr.com/7dhdj9

fin709

Anyone else end up multiplying conjugate after conjugate and somehow churning out 5+i in the part 1 of the complex numbers

sdio

DarraghF197 wrote: »

Yeah, I phrased my wording a bit bad there. When I got zero, I thought it couldn't right. So I changed the sum to let the n equal n rather than n-1. Then got -1/w which I was happy with.

But don't roots of unity always add up to 0?

Kremin

simplyno1 wrote: »

I got 46 degrees, used the tan m1 m2 formula... other peoples answers are just making me worry that i got the wrong answer when it asked you to sub in x = -4 to the first derivative

45* seems a little large though no? That would mean the height was 4km as well as the distance from the original, as 45* implied isosceles

sdio wrote: »

But don't roots of unity always add up to 0?

That's what I thought too, honestly I think it was 0. I let n = certain numbers and got 0 too.. so i dunno.

AlfaJack

fin709 wrote: »

Anyone else end up multiplying conjugate after conjugate and somehow churning out 5+i in the part 1 of the complex numbers

I think I got that too

YouKnowNothing

Thought it was a very easy paper personally, has anybody done it out yet?

Kremin

AlfaJack wrote: »

I think I got that too

Yeah I had an hour left so I checked everything manually and 5+i worked.

YouKnowNothing wrote: »

Thought it was a very easy paper personally, has anybody done it out yet?

I'll do it tonight when the paper is posted on examination.ie

DarraghF197

I don't get how people got 15*. You found the slope in the previous part. Considering the X-axis was the horizontal, it was just the tan of the slope, as in, the change in y over the change in x.

AnnaCU

simplyno1 wrote: »

I got 46 degrees, used the tan m1 m2 formula... other peoples answers are just making me worry that i got the wrong answer when it asked you to sub in x = -4 to the first derivative

I got 41, uhh everyones answers are different

Chef Tony

Kremin wrote: »

I'll do it tonight when the paper is posted on examination.ie

What is the actual time they put the papers up at?

Kremin

DarraghF197 wrote: »

I don't get how people got 15*. You found the slope in the previous part. Considering the X-axis was the horizontal, it was just the tan of the slope, as in, the change in y over the change in x.

I got the slope to be -.02 something, used tan0 and got 16.066*, then put 16* SOUTH OF EAST as the direction it was going in...

SteveZissou

For the last part of Q9 (time to reach the land 1km away), did anyone get 16 hours or something like that by integrating dt/dr?

Kremin

Chef Tony wrote: »

What is the actual time they put the papers up at?

Not sure. Some time later on i think though.

simplyno1

Kremin wrote: »

45* seems a little large though no? That would mean the height was 4km as well as the distance from the original, as 45* implied isosceles

Yeah im pretty sure my answer of 46 degrees is wrong. But i used the formula correctly, so im asking people what they got for the slope of the plane when x=-4, which was the part beforehand.

AnnaCU

simplyno1 wrote: »

can you remember what answer you got for subbing -4 into the first derivative? because that gave you the slope. so it would be a factor in the answer for the degrees... most likely how there is such a big difference. I got -0.02886 for that part.

Think i got that as well, but Im not sure :P I remember it being a small - figure

Kremin

simplyno1 wrote: »

Yeah im pretty sure my answer of 46 degrees is wrong. But i used the formula correctly, so im asking people what they got for the slope of the plane when x=-4, which was the part beforehand.

Well I got -.02 or something along those lines?